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[PPC64] Fix offset checks on rel24 call relocations. 

Adjusted the range check on a call instruction from 24 bits signed to
26 bits signed. While the instruction only encodes 24 bits, the target is
assumed to be 4 byte aligned, and the value that is encoded in the instruction
gets shifted left by 2 to form the offset. Also added a check that the offset is
indeed at least 4 byte aligned.

Differential Revision: https://reviews.llvm.org/D53401

llvm-svn: 344747
This commit is contained in:
Sean Fertile 2018-10-18 15:43:41 +00:00
parent b1f4a4b61d
commit 3acfe400a2
2 changed files with 68 additions and 1 deletions
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3
lld/ELF/Arch/PPC64.cpp
View File

@ -697,7 +697,8 @@ void PPC64::relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const {
break;
case R_PPC64_REL24: {
uint32_t Mask = 0x03FFFFFC;
checkInt(Loc, Val, 24, Type);
checkInt(Loc, Val, 26, Type);
checkAlignment(Loc, Val, 4, Type);
write32(Loc, (read32(Loc) & ~Mask) | (Val & Mask));
break;
}

66
lld/test/ELF/ppc64-call-reach.s Normal file
View File

@ -0,0 +1,66 @@
# REQUIRES: ppc
# RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t.o
# RUN: ld.lld --defsym callee=0x12010010 --defsym tail_callee=0x12010020 \
# RUN: %t.o -o %t
# RUN: llvm-objdump -d %t | FileCheck %s
# RUN: ld.lld --defsym callee=0x12010010 --defsym tail_callee=0x12010020 \
# RUN: %t.o -o %t
# RUN: llvm-objdump -d %t | FileCheck %s
# RUN: ld.lld --defsym callee=0xE010014 --defsym tail_callee=0xE010024 \
# RUN: %t.o -o %t
# RUN: llvm-objdump -d %t | FileCheck --check-prefix=NEGOFFSET %s
# RUN: not ld.lld --defsym callee=0x12010018 --defsym tail_callee=0x12010028 \
# RUN: %t.o -o %t 2>&1 | FileCheck --check-prefix=OVERFLOW %s
# RUN: not ld.lld --defsym callee=0x1001002D --defsym tail_callee=0x1001002F \
# RUN: %t.o -o %t 2>&1 | FileCheck --check-prefix=MISSALIGNED %s
# RUN: llvm-mc -filetype=obj -triple=powerpc64-unknown-linux %s -o %t.o
# RUN: ld.lld --defsym callee=0x12010010 --defsym tail_callee=0x12010020 \
# RUN: %t.o -o %t
# RUN: llvm-objdump -d %t | FileCheck %s
# RUN: ld.lld --defsym callee=0x12010010 --defsym tail_callee=0x12010020 \
# RUN: %t.o -o %t
# RUN: llvm-objdump -d %t | FileCheck %s
# RUN: ld.lld --defsym callee=0xE010014 --defsym tail_callee=0xE010024 \
# RUN: %t.o -o %t
# RUN: llvm-objdump -d %t | FileCheck --check-prefix=NEGOFFSET %s
# RUN: not ld.lld --defsym callee=0x12010018 --defsym tail_callee=0x12010028 \
# RUN: %t.o -o %t 2>&1 | FileCheck --check-prefix=OVERFLOW %s
# RUN: not ld.lld --defsym callee=0x1001002D --defsym tail_callee=0x1001002F \
# RUN: %t.o -o %t 2>&1 | FileCheck --check-prefix=MISSALIGNED %s
# OVERFLOW: ld.lld: error: {{.*}}.o:(.text+0x14): relocation R_PPC64_REL24 out of range: 33554436 is not in [-33554432, 33554431]
# OVERFLOW: ld.lld: error: {{.*}}.o:(.text+0x24): relocation R_PPC64_REL24 out of range: 33554436 is not in [-33554432, 33554431]
# MISSALIGNED: ld.lld: error: {{.*}}.o:(.text+0x14): improper alignment for relocation R_PPC64_REL24: 0x19 is not aligned to 4 bytes
# MISSALIGNED: ld.lld: error: {{.*}}.o:(.text+0x24): improper alignment for relocation R_PPC64_REL24: 0xB is not aligned to 4 bytes
.global test
.p2align 4
.type test,@function
test:
.Lgep:
addis 2, 12, .TOC.-.Lgep@ha
addi 2, 2, .TOC.-.Lgep@l
.Llep:
.localentry test, .Llep-.Lgep
mflr 0
std 0, 16(1)
stdu 1, 32(1)
bl callee
addi 1, 1, 32
ld 0, 16(1)
mtlr 0
b tail_callee
# Check that we are branching to the definitions, and not range-extending
# thunks.
# CHECK-LABEL: test
# CHECK: 10010014: {{.*}} bl .+33554428
# CHECK: 10010024: {{.*}} b .+33554428
# NEGOFFSET-LABEL: test
# NEGOFFSET: 10010014: {{.*}} bl .+33554432
# NEGOFFSET: 10010024: {{.*}} b .+33554432